Schizophrenia

• 1. Introduction

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  Schizophrenia is a mental disorder that shapes how a person hears, sees, thinks, and feels about the world around them. In 2022, the World Health Organization counted 24 million people living with it globally. It carries a lifetime prevalence of between 0.3% and 0.7% of all people, yet in areas of armed conflict that figure can climb as high as 6.5%. And here is a number that puts everything else in sharp relief: people with schizophrenia die, on average, 20 to 28 years earlier than the general population.

  The disorder does not announce itself suddenly in most cases. Up to 75% of those who will eventually receive a diagnosis first pass through a prodromal stage, a period of gathering signs that can precede the first episode of psychosis by as much as five years. What is happening in those years inside the brain, why it begins when it does, and what science and medicine can actually do about it are the questions this documentary will answer.

• 2. Three Kinds of Symptoms

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  Clinicians divide schizophrenia's symptoms into three distinct categories, and understanding all three is essential to understanding the disorder. The most visible cluster is the positive symptoms: hallucinations and delusions that are not part of ordinary experience. Hallucinations occur at some point in the lifetimes of roughly 80% of people with schizophrenia, and they most commonly take the form of hearing voices. The frequency of hallucinations involving multiple senses at once is double that of hallucinations involving only a single sense.

  Delusions often carry a persecutory quality. Distortions in the sense of self are also common, including the belief that others can hear one's thoughts, or that thoughts are being inserted from outside. Researchers have found that the content of these experiences is shaped by culture. Patients in the United Kingdom and United States tend to report hearing criticism and commands; patients in Africa, Asia, and the Middle East more often report religious messages. This holds true even among people who have migrated between regions, pointing to a cultural rather than a genetic origin for the difference.

  Negative symptoms, the second category, are absences rather than additions: flat affect, poverty of speech, inability to feel pleasure, withdrawal from relationships, and a deep loss of motivation. Apathy alone accounts for around half of the most frequently identified negative symptoms. These deficits are harder to treat than positive symptoms, and they affect daily functioning and quality of life more persistently.

  The third category is cognitive impairment, which touches an estimated 70% of people with schizophrenia. Verbal memory and attention are the most affected domains. These deficits are often visible before the first episode of psychosis, sometimes as early as childhood. Unlike positive symptoms, cognitive impairments do not respond meaningfully to antipsychotic medications, which is why coordinated care programs now include cognitive remediation therapy as a distinct element.

• 3. When It Begins

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  Onset typically falls between the late teens and the early thirties. In males, the peak incidence arrives in the early to mid-twenties; in females, in the late twenties. Onset before age 17 is called early-onset; onset before 13 is childhood schizophrenia. At the other extreme, onset between ages 40 and 60 is classified as late-onset, and onset past 60 as very-late-onset schizophrenia-like psychosis.

  The sex difference in timing is only part of a larger asymmetry. Estrogen, produced before menopause, has a dampening effect on dopamine receptors. That protection can be overcome by a heavy genetic burden, but it helps explain why women's rates of onset are later on average. After menopause, the incidence in females rises, effectively balancing over time what had looked like a male-dominant pattern in early adulthood.

  The period between a first episode of psychosis and the start of treatment has its own clinical name: the duration of untreated psychosis. That interval is linked to worse outcomes both in the short and long term, which is why research into early intervention programs has grown. Recognition during the prodromal stage, before psychosis has declared itself, could minimize the disruption to a young person's education and social development at precisely the age when those are forming.

• 4. A Web of Causes

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  Heritability estimates for schizophrenia run between 70% and 80%, meaning that 70% to 80% of individual differences in risk are associated with genetics. Having a first-degree relative with the disorder carries a 6.5% risk. More than 40% of identical twins of people with schizophrenia are also affected. Yet the DSM-5 notes that most people with schizophrenia have no family history of psychosis. The genetics are spread across many genes, each contributing a small effect; their combined weight can be expressed as a polygenic risk score explaining at least 7% of variability in liability.

  Around 5% of cases are at least partially attributable to rare structural variations called copy number variations. Some of these variants increase risk by as much as 20-fold and frequently co-occur with autism and intellectual disabilities.

  Genetic predisposition alone is not sufficient. Living in an urban environment during childhood or adulthood consistently doubles the risk of schizophrenia, even after controlling for drug use, ethnic group, and social group size. Maternal infections during pregnancy, including those from Toxoplasma gondii and Chlamydia, are also linked to elevated risk. Cannabis use during adolescence, childhood adversity, parental age at either extreme of the spectrum, and poor maternal nutrition all contribute smaller but real risks. Exposure to tramadol and desmopressin has also been associated with increased risk, while certain anti-protozoal medications appear to reduce it.

  At the neurobiological level, two models compete for primacy: the dopamine hypothesis, which links psychosis to misfiring of dopaminergic neurons, and the glutamate hypothesis, which points to reduced activity at NMDA receptors and disrupted connections between the thalamus and cortex. Crucially, these models are not mutually exclusive. Both appear to have a role, and drugs that affect both pathways are under active study.

• 5. Diagnosing and Misusing

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  Receiving a diagnosis of schizophrenia still requires no objective biological test. Diagnosis rests on observed behavior, a psychiatric history, and accounts from people close to the patient. Under DSM-5, two criteria must be met over one month, with significant impact on social or occupational functioning lasting at least six months. One of those criteria must be either delusions, hallucinations, or disorganized speech.

  The ICD-11, used widely in Europe, sets a shorter window of one month for the presence of symptoms. Both systems are frequently used across the world, and agreement between them is generally high in practice.

  The history of schizophrenia as a diagnosis is not a neutral one. Before the 1960s, nonviolent petty criminals and women who did not conform to domestic roles were sometimes categorized as schizophrenic. In the mid- to late 1960s in the United States, Black men involved in civil rights and Black Power activism were diagnosed with schizophrenia at disproportionately high rates; their political convictions were labeled as delusions. From the 1960s until 1989, psychiatrists in the USSR and the Eastern Bloc used a diagnosis called sluggish schizophrenia to confine thousands of political dissidents without any signs of psychosis, on the assumption that symptoms would eventually appear. That diagnosis is now discredited.

  The subtypes that once organized clinical understanding, including paranoid, disorganized, catatonic, and residual categories, were removed from DSM-5 in 2013 after proving difficult to distinguish reliably in practice.

• 6. Treatment Then and Now

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  The mid-1950s brought the first meaningful pharmacological option: chlorpromazine, the first typical antipsychotic. It worked by blocking D2 dopamine receptors. In the 1970s, clozapine, the first atypical antipsychotic, followed. Clozapine remains the most effective antipsychotic overall for treatment-resistant schizophrenia, benefiting around half of those who have not responded to other medications. Its serious potential side effect is agranulocytosis, a dangerous drop in white blood cell count, occurring in fewer than 4% of patients.

  Before these medications arrived, the options were grim. In the 1930s, insulin shock therapy induced comas through large doses of insulin. Electroconvulsive therapy was introduced by 1938. Psychosurgery, including the lobotomy, was carried out from the 1930s through the 1970s in the United States and through the 1980s in France; it is now recognized as a human rights abuse.

  In the UK, large mental hospitals called asylums began closing in the 1950s as antipsychotics made it possible to manage symptoms outside institutional walls. The US followed in the 1960s with its own deinstitutionalization movement. Community mental health services, supported employment, and drop-in centers grew to fill the gap, though countries with fewer social services still rely more heavily on long-term hospital stays.

  In September 2024, the US Food and Drug Administration approved xanomeline/trospium chloride, marketed as Cobenfy. It is the first cholinergic agonist approved for schizophrenia, working through a different mechanism than any prior antipsychotic, and a 2025 meta-analysis documented its improvement of schizophrenia symptoms.

• 7. Living With Schizophrenia

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  About half of those diagnosed will experience marked improvement over the long term with no further relapses. A small proportion recover completely. The other half face lifelong impairment. In 2016, schizophrenia was ranked the 12th most disabling condition in the world, and approximately 75% of people with the disorder experience ongoing disability with relapses. About 85% are unemployed.

  Almost 40% of people with schizophrenia die from complications of cardiovascular disease. The suicide rate is estimated at 5% to 6% overall, with 20 to 40% attempting suicide at least once. Smoking rates among people with schizophrenia run between 80% and 90%, compared to roughly 20% in the general population. Some researchers propose that heavy smoking represents an attempt to manage symptoms.

  The economic toll is substantial. In 2002, US healthcare and societal spending related to schizophrenia was estimated at 62.7 billion dollars. In the UK, annual expenditures reached 11.8 billion pounds in 2016, with roughly a third of that covering hospital, social care, and clinical treatment.

  Despite the stereotype reinforced by decades of film and media, most people with schizophrenia are not violent. They are more likely to be victims of violence than perpetrators. The risk of violence exists in specific subgroups, typically when schizophrenia co-occurs with a substance use disorder or antisocial personality disorder, and it is partly connected to deficits in facial emotion perception and social cognition rather than to the psychosis itself. Research into circulating microRNAs found in blood and cerebrospinal fluid may eventually offer an early biomarker for the disorder, a development that could shorten the duration between onset and effective treatment.